All but southern Missouri is within the Interior Plains. This is divided into two parts: Western Nebraska and Kansas are within the Great Plains, while the eastern parts of those states, plus all of Iowa and northern Missouri, are in the Central Lowland. Southern Missouri is mosty in the Interior Highlands, specifically the Ozark Plateaus, but the southeast corner of the state is in the Mississippi Alluvial Plain (part of the Atlantic Coastal Plain).
The Missouri River enters the areas from the north, forming the northeastern and eastern border of Nebraska, and the northeast border of Kansas, before crossing the state of Missouri west-east to join the Mississippi. That river forms the eastern borders of Iowa and Missouri.
These states are in the part of North America in which English-speakers and Christians are the majority.
There are two large cities in this area, both centered in Missouri.
I. Kansas City on the Missouri River, sits at the physiographic boundary between the Dessicated Till Plains and the Osage Plains. There are two cities of that name, the major one in Missouri, and its neighbor in Kansas.
II. Saint Louis
In the northwest corner of this area (and beyond) were the Cheyenne and in the west the Arapaho, both Algonquian.
Siouan languages such as Iowa, Oto, Omaha, Kansa, Missouri, Sioux and Osage were spoken in all of this area except the western edge and the Mississippi River valley. The area's old religion included the Plains Vision Quest, Sun Dance and Sacred Pipe.
In the center of Nebraska was a Caddoan group, the Pawnee.
The French were the first Europeans in the area, traveling by waterways. The English-speakers claimed the area after the buying the claims from the Spanish who had bought out the French claims. They subsequently violently displaced the indiginous inhabitants.
Slaves, descended from Africans, were brought into the southern half of this area by their purchasers.
north
northeast of Iowa
southeast of Iowan and east of all but southeast Missouri
east of the easternmost point of Missouri
east of the southeastern corner of Missouri
south
south of Kansas
west